My townhouse was built in the early 1980's, and since it was built, the state laws around which outlets are on a GFCI line have changed. The wiring itself is fine, just the receptacles need to be changed. I'm going to be placing in GFCI outlets where needed to bring it back up to code. This would require installing about half a dozen GFCI receptacles.
Unlike conventional outlets, GFCI outlets care about which wires are line (where power feeds from) and load (outlets that get power from the GFCI). Determining which is which can be tedious. My typical methodology for this has been to turn off the breaker, disconnect a NM wire, put caps on the wires that I disconnected, put the outlet back in place, and flip the breaker back on. If the outlet has power, I know that what is connected is "line", and if the outlet doesn't have power, I've found "load".
Is there an easier but still safe way to do this?